In the semiconductor industry, various manufacturing processes are typically carried out on a workpiece (e.g., a semiconductor wafer) in order to achieve various results thereon. Processes such as ion implantation, for example, can be performed in order to obtain a particular characteristic on or within the workpiece, such as limiting a diffusivity of a dielectric layer on the workpiece by implanting a specific type of ion. Conventionally, ion implantation processes are performed in either a batch process, wherein multiple workpieces are processed concurrently, or in a serial process, wherein a single workpiece is individually processed.
Traditional high-energy or high-current ion implanters typically utilized in batch ion implantation processes, for example, are operable to achieve an ion beam-line, wherein a plurality of workpieces are placed on a wheel or disk, and wherein the wheel is spun and radially translated through the ion beam, thus exposing all of the surface area of the workpieces to the ion beam at various times throughout the process. In a typical serial ion implantation process, on the other hand, an ion beam is typically scanned in two dimensions relative to a single workpiece. For example, in one conventional serial ion implantation system, the workpiece is uniformly translated in two dimensions with respect to a generally stationary ion beam, wherein a constant dose of ions from the ion beam is typically desired. Accordingly, the relative movement between the ion beam and the workpiece is typically desired to be constant when the ion beam is impinging on the workpiece. Such a constant relative movement between the ion beam and the workpiece is desirable in order to provide a substantially uniform implantation of ions across the surface of the workpiece.
However, the current or charge of a typical ion beam at the plane of the workpiece can vary significantly across a cross-section of the beam, and such variation can lead to a potential non-uniform implantation of ions to the workpiece in both batch processes and serial processes. Therefore, it is generally desirable to understand a profile and/or trajectory of the ion beam when it impacts the workpiece (i.e., at the workpiece plane). For example, an understanding of a charge distribution across a cross-section of the ion beam at the workpiece plane and/or a trajectory of the ion beam at the workpiece plane is desirable in order to determine an appropriate scan path of the ion beam with respect to the workpiece surface for implanting a proper dosage of ions and/or achieving a proper implant angle for the workpiece. Conventionally, such a profile measurement of the ion beam has been cumbersome and/or time consuming, and has frequently been based on assumptions of how the ion beam should appear for a given set of input parameters.
Therefore, a need currently exists for an apparatus, system, and method for determining a profile and/or trajectory of an ion beam at the workpiece plane, wherein a charge distribution across the ion beam can be empirically determined in a highly efficient manner.